////////////////////////////////////////////////////////////////////////////////
// The Loki Library
// Copyright (c) 2001 by Andrei Alexandrescu
// This code accompanies the book:
// Alexandrescu, Andrei. "Modern C++ Design: Generic Programming and Design 
//     Patterns Applied". Copyright (c) 2001. Addison-Wesley.
// Permission to use, copy, modify, distribute and sell this software for any 
//     purpose is hereby granted without fee, provided that the above copyright 
//     notice appear in all copies and that both that copyright notice and this 
//     permission notice appear in supporting documentation.
// The author or Addison-Wesley Longman make no representations about the 
//     suitability of this software for any purpose. It is provided "as is" 
//     without express or implied warranty.
////////////////////////////////////////////////////////////////////////////////

// Last update: June 20, 2001

#ifndef LOKITYPEINFO_INC_
#define LOKITYPEINFO_INC_

#include <typeinfo>
#include <cassert>

////////////////////////////////////////////////////////////////////////////////
// class TypeInfo
// Purpose: offer a first-class, comparable wrapper over std::type_info
////////////////////////////////////////////////////////////////////////////////

class TypeInfo
{
public:
	// Constructors
	TypeInfo(); // needed for containers
	TypeInfo(const std::type_info&); // non-explicit

	// Access for the wrapped std::type_info
	const std::type_info& Get() const;
	// Compatibility functions
	bool before(const TypeInfo& rhs) const;
	const char* name() const;

private:
	const std::type_info* pInfo_;
};

// Implementation

inline TypeInfo::TypeInfo()
{
	class Nil {};
	pInfo_ = &typeid(Nil);
	assert(pInfo_);
}

inline TypeInfo::TypeInfo(const std::type_info& ti)
	: pInfo_(&ti)
{ assert(pInfo_); }

inline bool TypeInfo::before(const TypeInfo& rhs) const
{
	assert(pInfo_);
	// type_info::before return type is int in some VC libraries 
	return pInfo_->before(*rhs.pInfo_) != 0;
}

inline const std::type_info& TypeInfo::Get() const
{
	assert(pInfo_);
	return *pInfo_;
}

inline const char* TypeInfo::name() const
{
	assert(pInfo_);
	return pInfo_->name();
}

// Comparison operators

inline bool operator==(const TypeInfo& lhs, const TypeInfo& rhs)
	// type_info::operator== return type is int in some VC libraries
{ return (lhs.Get() == rhs.Get()) != 0; }

inline bool operator<(const TypeInfo& lhs, const TypeInfo& rhs)
{ return lhs.before(rhs); }

inline bool operator!=(const TypeInfo& lhs, const TypeInfo& rhs)
{ return !(lhs == rhs); }    

inline bool operator>(const TypeInfo& lhs, const TypeInfo& rhs)
{ return rhs < lhs; }

inline bool operator<=(const TypeInfo& lhs, const TypeInfo& rhs)
{ return !(lhs > rhs); }

inline bool operator>=(const TypeInfo& lhs, const TypeInfo& rhs)
{ return !(lhs < rhs); }


////////////////////////////////////////////////////////////////////////////////
// Change log:
// June 20, 2001: ported by Nick Thurn to gcc 2.95.3. Kudos, Nick!!!
////////////////////////////////////////////////////////////////////////////////

#endif // LOKITYPEINFO_INC_